Processes for the conversion of organic waste present in an aqueous phase are known. In particular, it is known to bring the water/organic waste mixture to temperatures and pressures such that the water exceeds its critical point, thus resulting, where an oxidizing substance is present in the mixture, in the decomposition of the waste to simple chemical components of the CO2 and H2O type.
However, when the water/organic waste mixture, to which amounts of oxidizing agent capable of oxidizing all the waste have been added, is compressed and heated so that the water exceeds its critical point, the oxidation reaction which takes place produces large amounts of thermal energy which can affect the integrity of the walls of the reactor in which the reaction takes place.